Trash Talk - Exploring the memory management in the JVM

Are "stop-the-world" pauses killing your application's performance? Learn how modern JVM garbage collectors balance throughput, latency, and resource usage to keep your services responsive.

#1about 2 minutes

Why JVM memory management and structure matter

Understanding the JVM's automatic memory management and its structure, including the stack and heap, is crucial for application performance and responsiveness.

#2about 1 minute

How objects become garbage through reachability

An object becomes garbage and eligible for collection only when it is no longer reachable from any stack frame, including references held within other collections.

#3about 5 minutes

Understanding stop-the-world pauses and non-moving collectors

Garbage collection often requires stop-the-world pauses, and basic non-moving collectors like Mark and Sweep can lead to heap fragmentation over time.

#4about 7 minutes

Solving fragmentation with moving and generational collectors

Moving collectors like Mark-Compact and Copy, along with generational collection strategies, combat heap fragmentation and optimize for short-lived objects.

#5about 5 minutes

A tour of classic JVM garbage collectors

An overview of classic collectors including the single-threaded Serial, multi-threaded Parallel (throughput), and the now-deprecated Concurrent Mark Sweep (CMS).

#6about 3 minutes

Understanding the modern G1 garbage-first collector

The G1 collector is the default in modern JVMs, using a region-based approach to provide predictable pause times by focusing on areas with the most garbage.

#7about 3 minutes

Exploring low-latency and specialized collectors

Specialized collectors like Epsilon (no-op), Shenandoah, and ZGC are designed for specific use cases like ultra-low latency or massive heaps, often at the cost of throughput.

#8about 2 minutes

How ZGC achieves concurrency with colored pointers

Fully concurrent collectors like ZGC use techniques such as colored pointers and loaded value barriers to move objects and update references without long stop-the-world pauses.

#9about 1 minute

How to choose the right garbage collector

Selecting a garbage collector involves balancing the trade-offs between application throughput, latency from pause times, and overall resource consumption.